nix-config

My nix-config (NixOS + nix-darwin).

This configuration assumes this repository is cloned into ~/nix-config.

Directory Structure

├── flake.nix              # Main flake configuration
├── hosts/                 # Per-host system configurations
│   ├── onix/
│   ├── altaria/
│   ├── trubbish/
│   └── applin/
├── modules/
│   ├── common/
│   │   ├── hostclass/
│   │   └── home/          # User-specific home-manager config
│   ├── nixos/
│   │   ├── hostclass/
│   │   └── homelab/       # Self-hosted services
│   └── darwin/
│       └── hostclass/
├── apps/                  # Application dotfiles
├── meta/                  # Shared metadata
└── secrets.nix            # Agenix secrets configuration

Hostclass System

The configuration uses a layered hostclass inheritance system to promote modularity and code reuse. Hostclasses can define properties and inherit properties from one another, forming a directed acyclic graph. The graph should have a single root hostclass: base.

A system managed via this configuration will have $HOSTCLASS defined.

Configuration Pattern

Each host enables its hostclass via hostclass.<type>.enable = true.

# Example host configuration
{
  hostclass.server.enable = true;  # Automatically enables base
  # Additional host-specific configuration...
}

Secrets Management

Secrets are managed using agenix for age-encrypted secrets:

• Encrypted secrets stored in hosts/<name>/secrets/
• Secrets configuration defined in secrets.nix
• Age keys managed through SSH keys in meta/default.nix

Development

Adding a New Host

1. Create host directory: hosts/<hostname>/
2. Define host configuration in hosts/<hostname>/default.nix
3. Add hardware configuration: hosts/<hostname>/hardware.nix
4. Register in flake.nix using mkNixosHost or mkDarwinHost
5. Configure appropriate hostclass

Adding Homelab Services

For homelab services, add a module to modules/nixos/homelab/, following NixOS Modules convention.

Make sure to import the module in modules/nixos/homelab/default.nix.

Managing Secrets

1. Define secret in secrets.nix
2. Encrypt using agenix -e <secret-name>.age